The electrolyte is not a liquid, it’s semisolid gel. It came from research in ceramics.
Quote “”The US startup Ion Storage Systems is getting ready to launch their new solid state EV battery out of the pilot phase and into a high volume commercial-scale manufacturing line, with an assist from the 350-year-old materials specialist Saint-Gobain. If all goes according to plan, the EV battery of the future will be faster-charging, longer-ranging, less expensive, less reliant on rare earths and toxic chemicals, and more easily recyclable, helping to push gasmobiles out of the market sooner rather than later.””
https://cleantechnica.com/2023/12/18/new-solid-state-ev-battery-ceramic-brain/amp/